JP2002309229A - Detoxifying treatment agent for substance contaminated by organic halogen compound and treating method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detoxifying treatment agent for a substance and a treating method by decomposing an organic halogen compound for a short time without producing a harmful by-product and satisfying a legal restriction. SOLUTION: The detoxifying treatment agent for the substance to contaminated by the organic halogen compound comprises ion-nickel alloy powder. A nickel content of the alloy is 1-38% by weight by a measurement by an induction bonding plasma emission spectral analysis of a steel according to JIS G1258. The treating method using the detoxifying treating agent is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detoxifying agent for an object to be treated, such as soil, industrial waste, sludge, sludge, wastewater, and groundwater, which is contaminated with an organic halogen compound, and a method of treating the same using the same. It is.

[0002]

2. Description of the Related Art In recent years, environmental pollution problems due to organic halogen compounds such as TCE (trichloroethylene), PCE (tetrachloroethylene), dichloromethane, PCB (polychlorinated biphenyl), and dioxins have become remarkable in many parts of the world and have become a serious problem.

[0003] In order to solve these problems, a treatment agent for detoxifying soil, wastewater, groundwater and the like contaminated by an organic halogen compound and a treatment method thereof have been studied, and several technical reports or patents have been filed.

[0004] 1) As a method for treating polluted wastewater, groundwater, etc., an extraction / adsorption method, a pumping aeration method, etc. are known. Regeneration and disposal are required. In addition, it does not detoxify contaminated wastewater, groundwater and nearby soil itself, and cannot be said to be an essential detoxification method.

In recent years, treatment methods have been reported in which pollutants are decomposed and made harmless simply by mixing and spraying a metal catalyst. As a method of detoxifying with an iron-based catalyst, for example, Japanese Patent No. 263
No. 6171, Japanese Patent Publication No. 2-49158, and Japanese Patent Publication No. 49798/1992, require a pH control of contaminated wastewater and groundwater, and a deoxygenation treatment for supplying hydrogen gas and a reducing agent. It is difficult as a practical method. According to Sakizaki et al. [Industrial Water, Vol. 391, p. 29 (1991)], there is a technique for reducing and dechlorinating waste water and water contaminated with TCE using iron powder or Ni or Cu chemically plated iron powder. However, it is necessary to remove dissolved oxygen in contaminated wastewater and service water in order to suppress the performance deterioration of these catalysts over time, and furthermore, the range of the amount of active nickel plating is limited, and reproducibility becomes a problem. . Tokiohei 10-5131
No. 03 discloses a technique for decomposing dichloromethane with an Fe-Pd catalyst, but as a comparative example, iron powder plated with a nickel chloride solution has a slow decomposition rate and requires a long time to detoxify, Cannot be disassembled.

[0006] 2) As a method for treating contaminated soil, sludge, sludge, etc., a thermal desorption method and a thermal decomposition method in which a heating electrode is inserted into excavated soil or directly into the soil for heat treatment are known. In this method, the vicinity of the electrode is thermally decomposed, but the others are volatilized mainly on volatile organic halogen compounds on the ground and are not fundamental treatment methods. Although there is a bioremediation method using microorganisms, it is said that detoxification requires a long time, and cannot be applied to all soils, making complete detoxification impossible. Also, an iron-based decomposition catalyst was added to the contaminated soil,
As a technology for decomposing and treating pollutants, for example,
Although it is disclosed in Japanese Patent Application Laid-Open No. 1-235577, it cannot be decomposed in a short time. U.S. Pat. No. 5,616,253 discloses a technique for decomposing dichloromethane with an Fe-Pd catalyst. However, although an iron-nickel plating powder is described as a comparative example, the decomposition rate is slow and it is not long for detoxification. It was time-consuming and could not be completely disassembled.

[0007]

As described above, the conventional treatment method for the object to be treated contaminated with an organic halogen compound has problems that the treatment time is long, the cost is high, the treatment method is complicated, and the practicality is poor. ing. In particular, as a technology to add a metal catalyst such as iron to make it harmless, it is necessary to adjust the pH for contaminated wastewater and groundwater as a countermeasure against catalyst deterioration, and to dissolve dissolved oxygen. Since processing and complete disassembly cannot be performed, higher performance is required. Further, problems such as generation of harmful decomposition by-products remain. As an example of a catalyst that partially solves these problems, there is a nickel plating catalyst. However, there still remain problems such as an increase in environmental load and a reduction in reaction rate due to peeling or elution of a plated portion.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve these problems, and as a result, have completed the present invention. The present invention provides a detoxifying treatment agent and a treatment method using the same, whereby the concentration of a contaminating organic halogen compound can meet legally regulated values. That is, the nickel content in the iron-nickel alloy powder is JIS G125
8 is a detoxifying agent for an object to be treated, which is contaminated with an organic halogen compound in an amount of 1 to 38% by weight as measured by inductively coupled plasma emission spectroscopy of steel No. 8, and a processing method using the same.

Hereinafter, the present invention will be described in more detail.

The object to be treated by the detoxifying agent of the present invention is one which is contaminated with an organic halogen compound. Here, the organic halogen compound is not particularly limited as long as it is a compound described in the soil environmental standard item. For example, dichloromethane, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethylene, EDC (C
is-1,2-dichloroethylene), MC (1,1,1
-Trichloroethane), 1,1,2-trichloroethane, TCE (trichloroethylene), PCE (tetrachloroethylene), 1,3-dichloropropene and the like.

The detoxifying agent of the present invention is an iron-nickel alloy powder having a nickel content of 1 to 38% by weight as determined by a method of inductively coupled plasma emission spectroscopy of steel according to JIS G1258. If the nickel content is less than 1% by weight, the decomposition rate of the organic halogen compound is extremely slow, and it is necessary for a long period of time for detoxification. In addition, even if the amount added to the material to be treated is increased, the performance does not appear remarkably and the cost increases, and the legally regulated value cannot be cleared. On the other hand, the nickel content is 38% by weight.
If it exceeds, the decomposition reaction rate decreases. In addition, such a high nickel-containing powder is expensive and economically disadvantageous for its decomposition performance.

More specifically, when the nickel content of the iron-nickel alloy powder is in the range of 1 to 6.8% by weight, the α phase (iron-rich component, body-centered cubic crystal structure) is adjusted by adjusting the cooling rate during the production of the alloy powder. It can have a single phase or a two-phase crystal structure of α phase + γ phase (nickel-rich component, face-centered cubic crystal structure). Nickel content of 6.8 to 38
In the range of weight%, all have a two-phase type crystal structure of α phase + γ phase. It has been confirmed that the relationship between the performance and the crystal structure of the detoxifying agent for an organic halogen compound is in the order of a two-phase crystal structure alloy, an α-single-phase crystal structure alloy, and a nickel-plated iron powder.

The iron-nickel alloy powder as the detoxifying agent of the present invention has a specific surface area of 0.05 m ^2.
/ G and a particle size passing through a 200 μm sieve can improve the decomposition reaction rate and the contact probability of the object to be treated, and can reduce the harmfulness described in the soil environment standard items such as DCE in a shorter time. It is more preferable because organic halogen compounds can be decomposed.

The method for producing the detoxifying agent of the present invention is not limited, and includes a water or gas atomizing method, a dissolution pulverizing method, and the like.
Due to the manufacturing method, the shape of the treatment agent is spherical,
Dendrites, flakes, needles, squares, laminates, sponges and the like are included.

The detoxifying agent of the present invention contains the iron-nickel alloy powder as described above, but may contain an additive to such an extent that its effect is not impaired. The additives are not particularly limited, and include, for example, antioxidants, (electrolyte) reaction accelerators, dispersants and the like. Here, examples of the electrolyte include sodium chloride and sodium sulfate, and examples of the dispersant include activated carbon, alumina, zeolite, and silica gel.
Silica-alumina, and the like.

According to the detoxification treatment method of the present invention, the above-mentioned detoxification treatment agent is added to an object to be treated contaminated with an organic halogen compound, followed by treatment.

The amount of the detoxifying agent added is not particularly limited. However, since the contact probability with the organic halogen compound in the object to be treated is increased to increase the decomposition rate and become economically advantageous, 0% of the total amount of materials to be treated such as soil and groundwater.
Preferably it is in the range of 1 to 10% by weight.

Examples of the method of adding and mixing the detoxifying agent include: 1) Continuous and uniform mixing of excavated soil or pumped groundwater using a mixer, kneader or the like;
Alternatively, batch mixing using a mixing pit or the like, and 2) as an in-situ processing method, uniform mixing can be performed by injecting a detoxifying agent into soil, groundwater, or the like with air or water.

Further, according to the treatment method of the present invention, it is possible to add and mix the detoxifying agent of the present invention without requiring pH adjustment or deoxygenation treatment of the object contaminated with the organic halogen compound. Can be made harmless.

[0020]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

When the crystal structures of the treating agents prepared in the following Examples and Comparative Examples were determined by an X-ray microanalyzer, the nickel (Ni) content was 1%.
When the content was less than 1% by weight, the α phase was a single phase, when the content was in the range of 1 to 38% by weight, there were two phases of the α phase and the γ phase, and when it exceeded 38% by weight, the single phase was the γ phase.

Examples 1 to 6 and Comparative Examples 1 to 4 Tests of the detoxifying agent of the present invention with respect to a TCE-containing contaminated solution were conducted. In a 125 ml vial, a 100 mg / L aqueous TCE solution, an internal standard benzene dissolved in methanol, and the treating agent of the present invention were quickly added and sealed. 30 ° C,
The 200 rpm soak was maintained. This aqueous solution was not subjected to deoxygenation treatment and was adjusted to pH 6 to 7 with hydrochloric acid or sodium hydroxide.

The treating agent used was a nickel content of 0.01 to 42.4% by weight and a specific surface area of 0.2 as measured by inductively coupled plasma emission spectroscopy of steel according to JIS G1258.
１．２1.2 m ² / g, an iron-nickel alloy powder passed through a 75 μm sieve was used (Examples 1, 3 to 6 and Comparative Examples 1 to 3). As the 3.82% by weight nickel powder of Example 2, Kawasaki Steel KIP Sigmaalloy 415 was used. As the 99.7% by weight nickel powder of Comparative Example 4, nickel powder manufactured by Kojundo Chemical Laboratory Co., Ltd. was used, and a particle size product having passed through a 75 μm sieve was used. The amount added was 1 g (1% by weight based on the material to be treated).

As a method for analyzing the TCE concentration, JIS K
The TCE concentration was quantitatively analyzed with time using a head space method based on 0125 (test method for volatile organic compounds in water and wastewater). The ORP (mV) after the test was also measured. The results of these measurements are shown in Table 1 and FIG.

[0025]

[Table 1] In Examples 1 to 6, the TCE concentration was not more than 0.03 mg / L in the soil environment standard by 14 days. It was confirmed that ethylene was mainly used as a decomposition product, but no organic chlorine compound was generated as an environmental standard item such as DCE. The ORP value also shows a lower (lower) potential than the ORP of the TCE solution itself, suggesting that the TCE solution tends to undergo reductive decomposition. On the other hand, in the catalysts of Comparative Examples 1 and 2 having a nickel content of less than 1% by weight, the TCE concentration did not become 0.03 mg / L or less even after 14 days, and the nickel contents of Comparative Examples 3 and 4 were not increased. After 14 days, the catalyst exceeding 38% by weight did not have a TCE concentration of 0.03 mg / L or less and had a high ORP value.

Therefore, it was found that the use of the detoxifying treatment agents used in Examples 1 to 6 has a remarkable ability to decompose organic halogen compounds, and can satisfy legally regulated values.

Examples 7 to 11 and Comparative Examples 5 to 8 The ability of the present invention to decompose TCE-contaminated model soil was examined. Diatomaceous earth (Wako Pure Chemical, # 25-3
0) and 0.3 g of iron-nickel alloy powder (1.0% by weight based on soil) were mixed for 5 minutes.

To a 125 ml vial was added 9 ml (30% by weight based on soil) of the model soil mixed with the catalyst and deoxidized untreated water, and TCE (100 mg / L) and internal benzene dissolved in methanol were added. Added and sealed. The vial was reacted under the conditions of 30 ° C. and 200 rpm immersion.

The treating agent used was a nickel content of 0.05 to 78.5% by weight and a specific surface area of 0.2 measured by inductively coupled plasma emission spectroscopy of steel according to JIS G1258.
１．２1.2 m ² / g, an iron-nickel alloy powder passed through a 75 μm sieve was used (Examples 7, 9 to 11 and Comparative Examples 5 to 7). As the 3.82% by weight nickel powder of Example 9, Kawasaki Steel KIP Sigmaalloy 415 was used. As the 99.7% by weight nickel powder of Comparative Example 8, nickel powder manufactured by Kojundo Chemical Laboratory Co., Ltd., which passed through a 75 μm sieve, was used.

As a method of analyzing the TCE concentration, JIS
The TCE concentration was quantitatively analyzed over time using a head space method based on K 0125 (test method for volatile organic compounds in water and wastewater). The ORP (mV) after the test was also measured. The results of these measurements are shown in Table 2 and FIG.

[0031]

[Table 2] In Examples 7 to 11, the nickel content was 1.97 to 36.0.
By weight of the catalyst, the TCE concentration became less than 0.03 mg / L in the soil environment standard from 4 days to 6 days at the latest, confirming that the detoxifying agent of the present invention shows high resolution even in soil. did. In addition, it was confirmed that the decomposition by-product was mainly ethylene, and other organic chlorine compounds listed in the soil environmental standard were not generated. On the other hand, in Comparative Example 5, the TCE concentration did not become 30 mg / L or less even after 14 days, indicating that the nickel content in the catalyst was insufficient. Also, the catalysts of Comparative Examples 6 to 8 in which the nickel content exceeded 38% by weight had a high ORP value and a low reaction rate, so that the TCE concentration did not become 10 mg / L or less after 14 days.

Therefore, even in soil contaminated with an organic halogen compound, the ability to decompose an organic halogen compound is remarkable when the detoxifying agent used in Examples 7 to 11 is used, and the legally regulated value is cleared. I knew I could do it.

Examples 12 to 15 and Comparative Examples 9 to 11 Tests of the detoxifying agent of the present invention were performed on PCE-containing contaminated solutions. Pure water in a 125ml vial, 100ml
(10 mg / L) PCE, internal standard benzene dissolved in methanol, and a treating agent were quickly added and sealed. 30
C., 200 rpm immersion was maintained. This aqueous solution was not subjected to deoxygenation treatment and was adjusted to pH 6 to 7 with hydrochloric acid or sodium hydroxide.

The treating agent used was a nickel content of 0.01 to 42.4% by weight and a specific surface area of 0.2 as measured by inductively coupled plasma emission spectroscopy of steel according to JIS G1258.
１．２1.2 m ² / g, an iron-nickel alloy powder passed through a 75 μm sieve was used (Examples 12, 14, 15 and Comparative Examples 9 to 10). As the 3.82% by weight nickel powder of Example 13, Kawasaki Steel KIP Sigmaalloy 415 was used. As the 99.7% by weight nickel powder of Comparative Example 11, nickel powder manufactured by Kojundo Chemical Laboratory Co., Ltd. was used, and a particle size product passed through a 75 μm sieve was used. The amount added was 1 g (1% by weight based on the material to be treated).

As a method for analyzing the PCE concentration, JIS K
The PCE concentration was quantitatively analyzed with time using a head space method based on 0125 (test method for volatile organic compounds in water and wastewater). The ORP (mV) after the test was also measured. The results of these measurements are shown in Table 3 and FIG.

[0036]

[Table 3] In Examples 12 to 15, the PCE concentration was 0.01 mg / L or less by the soil environmental standard by 30 days. It was confirmed that no organic chlorine compound as an environmental standard item such as DCE was generated as a decomposition product. Further, the ORP value also shows a low (low) potential, suggesting that the PCE solution tends to undergo reductive decomposition. On the other hand, Comparative Examples 9-1
1 means that PCE concentration is 0.01mg after 30 days
/ L, and the ORP value was also high.

Therefore, it was found that the use of the detoxifying agents used in Examples 12 to 15 has a remarkable ability to decompose PCE, which is said to be hardly reductively decomposed, and can clear legally regulated values.

Examples 16 to 18 and Comparative Examples 12 to 14 DCE (cis-1,2-dichloroethylene), 10 m
A test of the detoxifying agent of the present invention with respect to a g / L contaminated solution was conducted. The test conditions are the same as in Examples 1 to 6. The test results are shown in Table 4 and FIG.

[0039]

[Table 4] In Examples 16 to 18, the DCE concentration was 0.04 mg / L or less by the soil environment standard by 14 days. Ethylene, ethane and the like were confirmed as decomposition products, and it was confirmed that no organic chlorine compound was produced as an environmental standard item. Also,
The ORP value also shows a low (low) potential, suggesting that the DCE solution tends to undergo reductive decomposition. On the other hand, in Comparative Examples 12 to 14, the DCE concentration did not reach the soil environment standard of 0.04 mg / L even after 14 days, and the ORP value was high.

Accordingly, it was found that the use of the detoxifying treatment agents used in Examples 16 to 18 has a remarkable ability to decompose DCE, which is said to be difficult to reduce and decompose, and can clear legally regulated values.

Examples 19 to 21 and Comparative Examples 15 to 17 MC (1,1,1, -trichloroethane), 10 mg /
A test of the detoxifying agent of the present invention with respect to the L-contaminated solution was performed. The test conditions are the same as in Examples 1 to 6. The test results are shown in Table 5 and FIG.

[0042]

[Table 5] In Examples 19 to 21, the MC concentration became 1 mg / L or less by the soil environment standard by 7 days. Ethylene, ethane and the like were confirmed as decomposition products, and it was confirmed that no organic chlorine compound was produced as an environmental standard item. The ORP value also shows a low (low) potential, indicating that the MC solution tends to undergo reductive decomposition. On the other hand, in Comparative Examples 15 to 17, the PCE concentration was 1 m in the soil environment standard even after 14 days.
g / L and the ORP value was high.

Therefore, it was found that the use of the detoxifying agents used in Examples 19 to 21 has a remarkable ability to decompose MC, which is said to be difficult to reduce and decompose, and can clear legally regulated values.

[0044]

As is clear from the above description, according to the detoxifying agent and the detoxifying method of the present invention, an organic halogen compound is decomposed in a short time, and no harmful by-products are generated, thereby making the detoxification possible. It can be processed and has the effect of being able to clear legally regulated values.

[0045]

[Brief description of the drawings]

FIG. 1 is a view showing the relationship between the nickel content in a detoxifying agent and the TCE concentration and ORP in a TCE-containing solution. In the figure, the X axis (horizontal axis) indicates nickel (N
i) The content (unit is% by weight), the left side of the Y axis (vertical axis) indicates the TCE concentration (unit: mg / L), and the right side of the Y axis (vertical axis) indicates the ORP (unit: mV). Further, a closed circle (●) indicates the TCE concentration after 14 days, and an open circle (○) indicates the ORP after 14 days.

FIG. 2 shows the relationship between the nickel content in the detoxifying agent, the TCE concentration, and the ORP for a TCE-containing soil. In the figure, the X-axis (horizontal axis) indicates the nickel (Ni) content (unit is% by weight) in the alloy, and the left side of the Y-axis (vertical axis) is TCE.
Concentration (unit: mg / L), ORP on right side of Y axis (vertical axis)
(Unit is mV). In addition, a closed circle (●) indicates the TCE concentration in the soil after 14 days, and an open circle (）) indicates the ORP in the soil after 14 days.

FIG. 3 is a diagram showing a relationship between a nickel content in a detoxifying agent, a PCE concentration, and an ORP in a PCE-containing solution. In the figure, the X axis (horizontal axis) indicates nickel (N
i) The content (unit is% by weight), the left side of the Y-axis (vertical axis) indicates PCE concentration (unit: mg / L), and the right side of the Y-axis (vertical axis) indicates ORP (unit: mV). Further, a closed circle (）) indicates the TCE concentration after 30 days, and a white circle (○) indicates the ORP after 30 days.

FIG. 4 is a diagram showing a relationship between a nickel content in a detoxifying agent, a DCE concentration, and an ORP in a DCE-containing solution. In the figure, the X axis (horizontal axis) indicates nickel (N
i) The content (unit is% by weight), the left side of the Y-axis (vertical axis) indicates DCE concentration (unit: mg / L), and the right side of the Y-axis (vertical axis) indicates ORP (unit: mV). In addition, a closed circle (●) indicates the DCE concentration after 14 days, and a white circle (○) indicates the ORP after 14 days.

FIG. 5 is a view showing the relationship between the nickel content in the detoxifying agent, the MC concentration, and the ORP in the MC-containing solution. In the figure, the X-axis (horizontal axis) indicates the nickel (Ni) content (unit is% by weight) in the alloy, and the left side of the Y-axis (vertical axis) is M
C concentration (unit: mg / L), right side of Y axis (vertical axis) is OR
P (unit is mV). In addition, a black circle (●) indicates the MC concentration after 14 days, and a white circle (○) indicates the ORP after 14 days.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C02F 1/70 C07B 35/06 4H006 11/00 C07C 19/05 4H039 C07B 35/06 21/073 C07C 19/05 21 / 10 21/073 21/12 21/10 G01N 33/00 D 21/12 33/18 101 G01N 33/00 C07B 61/00 300 33/18 101 B09B 3/00 304K // C07B 61/00 300 F term ( Reference) 2E191 BA12 BB01 BC01 BD13 4D004 AA46 AB06 CA34 CC09 4D038 AA08 AB14 BB15 4D050 AA12 AB19 BA00 BC04 4D059 AA03 BK30 4H006 AA05 AC13 BA19 BA21 BA82 BA85 BC32 BC34 EA02 EA03 4H039 CA20 CD20 CE90

Claims (5)

[Claims] 1. A substrate contaminated with an organic halogen compound comprising iron-nickel alloy powder and having a nickel content of 1 to 38% by weight as measured by inductively coupled plasma emission spectroscopy of steel according to JIS G1258. Detoxifying agent for processed materials. 2. The detoxifying treatment for an object to be processed according to claim 1, wherein the iron-nickel alloy has a two-phase type crystal structure of α phase and γ phase determined by an X-ray microanalyzer method. Agent. 3. It has a specific surface area of 0.05 m ² / g or more,
The detoxifying agent for an object to be treated according to claim 1 or 2, comprising an iron-nickel alloy powder having a particle size passing through a sieve of 200 µm. 4. A treatment object contaminated with an organic halogen compound, characterized in that the object to be treated contaminated with the organic halogen compound is added, mixed and treated. Detoxification treatment method for processed objects. 5. The method according to claim 4, wherein the amount of the detoxifying agent added is 0.1 to 10% by weight based on the total amount of the object to be treated. Detoxification method.